The C Train is one of only three lines of the New York City subway whose route is entirely on trackage built by the Independent subway system (the others being the E and G). It is underground along its entire route (a feat it shares only with the E Train and the R) and is a local service companion to the A express along its entirety.

The trackage where the C train runs (The Central Park West and the Eighth Avenue Line in Manhattan, and the Fulton Line in Brooklyn), was built as part of the initial Independent subway in the late 20s and early 30s. The farthest outlying section in Brooklyn, such as the Euclid avenue stop, was part of the last section of the Independent build before the war and as such it has very Art Deco station architecture.

The first service to resemble the current C was the AA local along this same route. Before the MTA went to all single letters in 1986, the C was called the CC.

The C Train currently runs almost exclusively R32 rolling stock, rather ugly cars from the mid 60s. It is also the current home of the R110B test train.

In January of 2005, a fire caused by a homeless person, at the Chambers Street-World Trade Center station messed up the relay system controlling the (A) and (C) trains, with the worst between Broadway-Nassau Streets and Canal Street. All signals were permanantly set to red, and train operators had to stop at every signal to key by, or rig the signal to green. To this effect, the MTA could only operate a small amount of service, without massive congestion problems. Which meant cancellation of (C) trains, and converting the (A) to a local. (A) service to/from Rockaway Park was suspended as well.

At the time New York City Transit president (NYCTA is the agency operated by the MTA, that run the subways and buses in NYC) Laurence Reuter announce that it may take 3 to 5 years to resume normal service. Luckily that was an off estimate. 70% of service was resumed on Valentine's Day, 80% in late March, and full service in April.

Another note, the (B) and (C) trains swapped northern terminals in 1998, for better acess to yards and equipment. (C) trains now ran to Washington Heights-168th Street, and (B) trains ran to the Bronx, or Harlem-145th Street, depending of the time of day. (C) trains now ran full-length on weekends, allowing the (A) to run express in Manhattan and Brooklyn 7 days a week. (C) trains still don't run at night, and still have the same 8 car trains. With the arrival of the new R160 subway cars, the future of the R38 and R32 cars, which see service on the (C) are uncertain.